Neptune Canada just posted this video of a Batman-shaped (actually more like the Batwing)... thing floating over the surface of the deep sea bottom.

They don't know what it is. And I'm not entirely sure I do either!! Sea Cucumber? Jellyfish? Ctenophore? Cthulhu's Dandruff flakes? What could it be? WHEEE!

THIS is the fun part of science! See something totally weird that you don't recognize and proceed to find OUT! Got a good suggestion? Or better yet-is there a grad student/engaging scientist out there who knows what it is??

Deming & Colwell sampled the microbial faunas from the intestines of these various holothurian species, sampling different cultures from the gut (# 2) and parallel to stomach in humans) versus the hindgut (#3) (parallel to our long intestines)..Here's a nice image from Amaro et al that shows this...

Fig.2 from Amaro et al.

It turns out that microbes..specifically bacteria WERE present in the intestinal lining of these sea cucumbers! And in significant abundance!!

Here's what they looked like..

(Fig. 5. Transmission electron micograph of the bacteria in the intestinal lining)

These microbial floras were 1.5 to THREE times higher in sediments that had been recently ingested than those where present in the surrounding sediments.

The abundance of these microbes was HIGHEST in the hindgut..where digestion in the intestine occurs (again the equivalent of our long intestine).

But perhaps what was most significant was that these microbial populations were actually MORE ACTIVE under deep-sea pressure (about 400 atmospheres given that "home" pressure was from about 4000 meters!). "Pressure loving" bacteria are what's known as barophilic (etymological note-that's "baros" for pressure-like in barometer and "philos" for attraction or lovin'...oh yeah...)

Dynamics of the bacterial/microbial community:

Various trivia of sea cucumber digestion. By their estimates, it took about 16 HOURS for the organic materials in the sediment to be affected and cleared through the gut. This resulted in about 105 grams of sediment passing through one animal per day (which may not seem like much-but consider that its deep-sea mud and how many animals are in play)

Commensal Flora? The authors argued that the bacteria assisted or was involved in digestion or in their terms..."transformation" of the organic materials present in the ingested sediments

Food? They did not rule out the possibility that the bacteria were somehow directly involved in providing nutrients via the gut to the sea cucumbers.. perhaps as food? or perhaps contributing to the minerals or the energy of the sediment being digested??

At this juncture I can take a moment to further embellish the answer: Why would deep-sea sea cucumbers make lousy pets? Well, these things have a community of microbes that live in their intestine that they need to survive. And they are MOST successful at deep-sea pressure! (400 atm!)

So-food would likely have a lot of problems metabolizing in these beasts at the surface..assuming they could get the right kind of fine quality, organic scum to begin with!

Yes, I've seen them alive, they are THAT glamorous. Sometimes they are purple.

Amaro and her associates characterized the microbial community within Molpadia with DNA fingerprinting and discovered that in fact, these communities can be quite diverse, with many lineages of bacteria present...

But perhaps what is most interesting was their study that compared two populations of Molpadia-each population present in a different canyon. Each canyon with a different nutritonal setting!

How might these different food rich/poor settings affect the microbe fauna of each sea cucumber population??

The authors compared the bacterial communities present in a canyon with a sediment bottom that was rich in organic matter (i.e., food!) versus one which was poor in organic food.

They found that in the canyon with a rich sediment bottom with lots of yummy organic food, the Molpadia did not need to develop a specialized community of gut bacteria!

In contrast, the population of Molpadia present where the sediment was poorer DID have a more specialized community of bacteria.. Does this augment or provide further nutrients to the host cucumber?

So-getting back to some of the questions asked earlier.. these bacterial communites seem to be an important part of how these weird critters live their lives- as they trundle around on the sea bottom picking up delicious scum from the abyssal mud of the sea bottoms! Perhaps they carry it with them or perhaps they are feeding on them? Many questions remain!

It always seems kind of a funny contrast to me as I observe individuals become so paranoid about bacteria on door knobs and small microbes everywhere in the air.. that at 4000 to 5000 meters below the Earth's surface bacteria (yogurt?) are actually essential to this abundant form of weird life....

Well, I am STILL on that ophiuroid kick and wanted to show you guys even MORE of the strange and wonderous beauty of brittle stars. Except, today, I thought I'd show you some from the deep-sea!

These are all members of the familyOphiuridae, one of the world's most diverse groups that occur all over the world, but particularly well represented in the deep-sea (>200 meters) with many more new species likely to be discovered.

Most of the ones shown below belong to the genus Amphiophiura which is distributed throughout the world...but down at the bottom you'll see one of the more... UNUSUAL brittle stars that most people would ordinarily never get to see!

What's important to realize about most of these species is that, aside from the fact that we know they exist-we know almost NOTHING ABOUT THEM.

But they are interesting-and frankly, not everyone gets to see them like this-so I thought it fun to show the world! Plus, with Halloween just around the corner..I thought some weird echinoderms would add to the overall ambience!

So here's Amphiophiura insolita(=Ophiura monaria) from Hawaii. The disk is about the size of a dime.Amphiophiura pomphophora(from Japan-the Albatross Collection)Amphiophiura coronatafrom the Caribbean (Puerto Rico!). Weird how the primary disk plates form that sort of pentagonal pattern on the center! Also, note how small it is-that's a penny in the background for scale!When these are found, they can be abundant...but not much is known about them..Amphiophiura bullata convexa from the North AtlanticThe animal's disk is strikingly dome-shaped and kinda looks like a soccer ball...Amphiophiura superba(from Baja California, Mexico-the Albatross Collection). These can be quite thick and are surprisingly large. Sometimes, its hard to believe they are alive!Stegophiura sterea from Japan!And just for kicks.. what does the MOUTH and/or oral surface look like? Here ya' go! and one of the strangest...a brittle star that LOOKS like a starfish... I give you..Astrophiura marionaefrom off the Channel Islands in California!!But other species in this genus are found all over the world.. Go here to see which ones!!Astrophiura is a weird beast and is unusual in that it displays a convergent/parallel/analogous appearance shared with the weird deep-sea starfish which are members of the Caymanostellidae.

Now, ANYONE could just do a blog about cephalopods and frankly, there are several good ones (see the sidebar) that focus entirely on cephalopods. So, what odd or unique thing can the Echinoblog bring to the table?

But here is a creative fellow (from website Corey's Head) who has applied Photoshop to several Japanese monster toys (mostly about 6 to 9 inches tall) with cephalopod themes!! He has applied some scenic backgrounds from the Washington state area into..well... these cephalopod monster inspired masterpieces!

And here's an odd onefrom an old Japanese science fiction show called Barom-1. . Unfortunately, I'm not sure what its called other than "Ammonite Head Monster" .... but uh..yeah, that's pretty much what it is...

and if that wasn't enough? Go take a look at this New Zealand-TePapa Museum video of what must be one of the world's LARGEST ammonites! (a fossil cephalopod from the Mesozoic!)

Tuesday, October 4, 2011

Echinoderms do a lot of weird and wonderful things-but the truth is that we know very little about most of them. Sometimes, the path to getting people interested and contributing to our study is simply being exposed to different species. And so, I present some images here of some striking species that most people may not be very familiar with

Probably the award winner of "great potential to study unknown diversity" in echinoderms is the ophiuroids or brittle stars. There are probably more species of brittle stars than any other living echinoderm. The World Ophiuroidea Database lists 2,122 species and based on what I've seen in museum collections I bet we could easily get up to 3,000 if not more.

Ophiuroids are often very small (although they are very abundant)-and so, most people don't get to appreciate the sheer diversity and aesthetic.. Especially not in the way that scientists might.

Most of the species below have a disk that is about Susan-B-Anthony size and smaller.

So, today, I thought I would just show some species in the genus Ophiolepis which have some neat plate arrangements (i.e, the skeletal structure on the arms and disk) and actually retain colors and patterns after having been preserved!

Ophiolepis is found all over the world with many species in shallow tropical Atlantic and Indo-Pacific waters.

We have records of these species-but we know almost NOTHING about the biology or ecology of most of these animals.

Click on the images below and see them up close!

The Latin breakdown of the genus name Ophiolepis breaks down to "Ophio-" refers to the snake like body (this is a common component of ophiuroid names) and "-lepis" refers to the scale-like plates..

Click on each name to head to the taxonomic summary in the World Ophiuroidea Database.

The species name "superba" likely makes reference to approval of the very attractive appearance.

The patterns are variable among individuals. The patterns in preserved specimens look pretty much look the same as in the living animals... Is there significance? Is it natural variation? Related to environment?

Ophiolepis elegansA relatively familiar species (insofar as brittle stars are familiar!) from the Gulf of Mexico and the tropical Atlantic. In shallow to shelf depths (~10-100 m)

Ophiolepis ailsae. This species was discovered only in 1987!!! It occurs in the tropical Atlantic in the Caribbean and Gulf of Mexico.

This species was named for the noted echinoderm researcher at the British Museum Ailsa Clark.Ophiolepis variegata A tropical shallow water species from the East Pacific, around Mexico and Baja CaliforniaOphiolepis cincta. This is a tropical Indo-Pacific species that also occurs in shallow water. Other than some descriptive and reproductive information, we know very little about the biology of this species.Brittle stars like this always trigger a lot of questions to me.

Why are they so ornately colored? Is there anything adaptive about the calcified scalar plates? About the patterns and colors?

About Me

I pursue starfish related adventure around the world with a critical eye and an appreciation for weirdness.
Support has been courtesy of the National Science Foundation but the views and opinions presented herein are mine and do not reflect the opinions of them or any affiliated institutions.
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